SAN DIEGO--Researchers investigating why anesthesiologists are more prone to addiction to certain drugs than other physicians have found traces of intravenously delivered anesthetics in the air of operating rooms. Chronic environmental exposure to such compounds may sensitize brain reward pathways and make anesthesiologists more likely to abuse drugs, according to the investigators.
It's long been recognized that anesthesiologists are especially susceptible to abusing drugs, particularly opiate-based drugs similar to those used in general anesthesia. In Florida in 2003, for example, anesthesiologists represented less than 6% of all physicians but made up almost 25% of the physicians monitored for substance-abuse disorders.
The prevailing assumption has been that anesthesiologists' access to potent opiates largely explained their vulnerability. But other physicians with similar access don't have similarly high rates of opiate-related substance abuse.A group led by addiction specialist Mark Gold of the University of Florida, Gainesville, and anesthesiologist Richard Melker recently pursued a different hypothesis: that anesthesiologists are primed for drug abuse because they inhale small amounts of anesthetics in the operating room. There are potential precedents to such a phenomenon, which researchers call sensitization. Studies suggest that house painters are prone to alcoholism because of exposure to solvents, for example.Gold, Melker, and their colleagues used a mass spectrometer to examine the air in the operating rooms during cardiac bypass surgeries in which anesthesiologists intravenously delivered the powerful anesthetics propofol or fentanyl. Both of the compounds were found in the operating room air and at higher concentrations in the space between the anesthesiologist and patient, Matt Warren of the Florida team reported here 23 October at the annual meeting of the Society for Neuroscience.The researchers suspect that the two compounds are exhaled by the anesthetized patients. They're now collecting blood samples of anesthesiologists during operations to see if they can detect the presence of the anesthetics. They also intend to expose rodents to the same air concentrations of the compounds found in the operating rooms and test whether those animals are more susceptible to drug addiction.R. Lawrence Sullivan, an anesthesiologist at O'Connor Hospital in San Jose, California, and chair of the American Society of Anesthesiologists' communications committee, notes that his field decades ago developed ways to remove gaseous anesthetics from the air of operating rooms. But he never suspected that intravenous anesthetics might also contaminate the air. "I have a hard time thinking this would have any realistic consequences," he says.